InVivoMAb polyclonal Syrian hamster IgG
Product Details
The polyclonal Syrian hamster IgG is purified from Syrian hamster serum. It is ideal for use as a non-reactive control IgG for Syrian hamster antibodies in most in vivo and in vitro applications.Specifications
| Isotype | Syrian hamster IgG |
|---|---|
| Recommended Dilution Buffer | InVivoPure pH 7.0 Dilution Buffer |
| Conjugation | This product is unconjugated. Conjugation is available via our Antibody Conjugation Services. |
| Formulation |
PBS, pH 7.0 Contains no stabilizers or preservatives |
| Endotoxin |
<2EU/mg (<0.002EU/Ī¼g) Determined by LAL gel clotting assay |
| Purity |
>95% Determined by SDS-PAGE |
| Sterility | 0.2 Āµm filtration |
| Purification | Protein G |
| RRID | AB_1107782 |
| Molecular Weight | 150 kDa |
| Murine Pathogen Tests |
Ectromelia/Mousepox Virus: Negative Hantavirus: Negative K Virus: Negative Lactate Dehydrogenase-Elevating Virus: Negative Lymphocytic Choriomeningitis virus: Negative Mouse Adenovirus: Negative Mouse Cytomegalovirus: Negative Mouse Hepatitis Virus: Negative Mouse Minute Virus: Negative Mouse Norovirus: Negative Mouse Parvovirus: Negative Mouse Rotavirus: Negative Mycoplasma Pulmonis: Negative Pneumonia Virus of Mice: Negative Polyoma Virus: Negative Reovirus Screen: Negative Sendai Virus: Negative Theilerās Murine Encephalomyelitis: Negative |
| Storage | The antibody solution should be stored at the stock concentration at 4Ā°C. Do not freeze. |
Additional Formats
Recommended Products
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Recommended Dilution Buffer
InVivoPure pH 7.0 Dilution Buffer
Bradley, T., et al. (2020). "Immune checkpoint modulation enhances HIV-1 antibody induction" Nat Commun 11(1): 948. PubMed
Eliciting protective titers of HIV-1 broadly neutralizing antibodies (bnAbs) is a goal of HIV-1 vaccine development, but current vaccine strategies have yet to induce bnAbs in humans. Many bnAbs isolated from HIV-1-infected individuals are encoded by immunoglobulin gene rearrangments with infrequent naive B cell precursors and with unusual genetic features that may be subject to host regulatory control. Here, we administer antibodies targeting immune cell regulatory receptors CTLA-4, PD-1 or OX40 along with HIV envelope (Env) vaccines to rhesus macaques and bnAb immunoglobulin knock-in (KI) mice expressing diverse precursors of CD4 binding site HIV-1 bnAbs. CTLA-4 blockade augments HIV-1 Env antibody responses in macaques, and in a bnAb-precursor mouse model, CTLA-4 blocking or OX40 agonist antibodies increase germinal center B and T follicular helper cells and plasma neutralizing antibodies. Thus, modulation of CTLA-4 or OX40 immune checkpoints during vaccination can promote germinal center activity and enhance HIV-1 Env antibody responses.
Klepsch, V., et al. (2020). "Targeting the orphan nuclear receptor NR2F6 in T cells primes tumors for immune checkpoint therapy" Cell Commun Signal 18(1): 8. PubMed
BACKGROUND: NR2F6 has been proposed as an alternative cancer immune checkpoint in the effector T cell compartment. However, a realistic assessment of the in vivo therapeutic potential of NR2F6 requires acute depletion. METHODS: Employing primary T cells isolated from Cas9-transgenic mice for electroporation of chemically synthesized sgRNA, we established a CRISPR/Cas9-mediated acute knockout protocol of Nr2f6 in primary mouse T cells. RESULTS: Analyzing these Nr2f6(CRISPR/Cas9 knockout) T cells, we reproducibly observed a hyper-reactive effector phenotype upon CD3/CD28 stimulation in vitro, highly reminiscent to Nr2f6(-/-) T cells. Importantly, CRISPR/Cas9-mediated Nr2f6 ablation prior to adoptive cell therapy (ACT) of autologous polyclonal T cells into wild-type tumor-bearing recipient mice in combination with PD-L1 or CTLA-4 tumor immune checkpoint blockade significantly delayed MC38 tumor progression and induced superior survival, thus further validating a T cell-inhibitory function of NR2F6 during tumor progression. CONCLUSIONS: These findings indicate that Nr2f6(CRISPR/Cas9 knockout) T cells are comparable to germline Nr2f6(-/-) T cells, a result providing an independent confirmation of the immune checkpoint function of lymphatic NR2F6. Taken together, CRISPR/Cas9-mediated acute Nr2f6 gene ablation in primary mouse T cells prior to ACT appeared feasible for potentiating established PD-L1 and CTLA-4 blockade therapies, thereby pioneering NR2F6 inhibition as a sensitizing target for augmented tumor regression. Video abstract.
Wang, Q., et al. (2019). "Single-cell profiling guided combinatorial immunotherapy for fast-evolving CDK4/6 inhibitor-resistant HER2-positive breast cancer" Nat Commun 10(1): 3817. PubMed
Acquired resistance to targeted cancer therapy is a significant clinical challenge. In parallel with clinical trials combining CDK4/6 inhibitors to treat HER2+ breast cancer, we sought to prospectively model tumor evolution in response to this regimen in vivo and identify a clinically actionable strategy to combat drug resistance. Despite a promising initial response, acquired resistance emerges rapidly to the combination of anti-HER2/neu antibody and CDK4/6 inhibitor Palbociclib. Using high-throughput single-cell profiling over the course of treatments, we reveal a distinct immunosuppressive immature myeloid cell (IMC) population to infiltrate the resistant tumors. Guided by single-cell transcriptome analysis, we demonstrate that combination of IMC-targeting tyrosine kinase inhibitor cabozantinib and immune checkpoint blockade enhances anti-tumor immunity, and overcomes the resistance. Furthermore, sequential combinatorial immunotherapy enables a sustained control of the fast-evolving CDK4/6 inhibitor-resistant tumors. Our study demonstrates a translational framework for treating rapidly evolving tumors through preclinical modeling and single-cell analyses.
Su, W., et al. (2019). "The Polycomb Repressor Complex 1 Drives Double-Negative Prostate Cancer Metastasis by Coordinating Stemness and Immune Suppression" Cancer Cell 36(2): 139-155.e110. PubMed
The mechanisms that enable immune evasion at metastatic sites are poorly understood. We show that the Polycomb Repressor Complex 1 (PRC1) drives colonization of the bones and visceral organs in double-negative prostate cancer (DNPC). In vivo genetic screening identifies CCL2 as the top prometastatic gene induced by PRC1. CCL2 governs self-renewal and induces the recruitment of M2-like tumor-associated macrophages and regulatory T cells, thus coordinating metastasis initiation with immune suppression and neoangiogenesis. A catalytic inhibitor of PRC1 cooperates with immune checkpoint therapy to reverse these processes and suppress metastasis in genetically engineered mouse transplantation models of DNPC. These results reveal that PRC1 coordinates stemness with immune evasion and neoangiogenesis and point to the potential clinical utility of targeting PRC1 in DNPC.
Binnewies, M., et al. (2019). "Unleashing Type-2 Dendritic Cells to Drive Protective Antitumor CD4(+) T Cell Immunity" Cell 177(3): 556-571.e516. PubMed
Differentiation of proinflammatory CD4(+) conventional T cells (T(conv)) is critical for productive antitumor responses yet their elicitation remains poorly understood. We comprehensively characterized myeloid cells in tumor draining lymph nodes (tdLN) of mice and identified two subsets of conventional type-2 dendritic cells (cDC2) that traffic from tumor to tdLN and present tumor-derived antigens to CD4(+) T(conv), but then fail to support antitumor CD4(+) T(conv) differentiation. Regulatory T cell (T(reg)) depletion enhanced their capacity to elicit strong CD4(+) T(conv) responses and ensuing antitumor protection. Analogous cDC2 populations were identified in patients, and as in mice, their abundance relative to T(reg) predicts protective ICOS(+) PD-1(lo) CD4(+) T(conv) phenotypes and survival. Further, in melanoma patients with low T(reg) abundance, intratumoral cDC2 density alone correlates with abundant CD4(+) T(conv) and with responsiveness to anti-PD-1 therapy. Together, this highlights a pathway that restrains cDC2 and whose reversal enhances CD4(+) T(conv) abundance and controls tumor growth.
- Immunology and Microbiology,
Characterisation of an autochthonous mouse ccRCC model of immune checkpoint inhibitor therapy resistance.
In Sci Rep on 5 June 2025 by Peighambari, A., Huang, H., et al.
PubMed
Many metastatic clear cell renal cell carcinomas (ccRCC) are resistant to immune checkpoint inhibitor therapies, however the mechanisms underlying sensitivity or resistance remain incompletely characterised. We demonstrate that ccRCCs in the Vhl/Trp53/Rb1 mutant mouse model are resistant to combined anti-PD-1/anti-CTLA-4 therapy alone and in combination with additional therapeutic agents that reflect current ccRCC clinical trials. However, in some animals in vivo checkpoint therapy allowed isolated splenic T cells to recognise cultured ccRCC cells from the same animal, implicating the tumour microenvironment in suppression of T cell activation. We identified putative immunosuppressive myeloid cell populations with features similar to myeloid cells in the microenvironment of human ccRCC. The expression patterns of immune checkpoint ligands in both the mouse model and in human ccRCC suggests that several checkpoint systems other than PD-1 and CTLA-4 are likely to represent the dominant T cell suppressive forces in ccRCC. Our findings characterise an autochthonous mouse ccRCC model of immune checkpoint inhibitor therapy resistance and pave the way for a systematic functional dissection of the identified potential molecular barriers to effective immune therapy of ccRCC.
- Cancer Research,
- Immunology and Microbiology
Antigen-presenting cancer-associated fibroblasts in murine pancreatic tumors differentially control regulatory T cell phenotype and function via CXCL9 and CCL22
In bioRxiv on 1 April 2025 by Maru, S. Y., Wetzel, M., et al.
- Immunology and Microbiology
KRASG12D-Specific Targeting with Engineered Exosomes Reprograms the Immune Microenvironment to Enable Efficacy of Immune Checkpoint Therapy in PDAC Patients
In medRxiv on 6 March 2025 by LeBleu, V. S., Smaglo, B. G., et al.
- Cancer Research
Inhibitors of oncogenic Kras specifically prime CTLA4 blockade to transcriptionally reprogram Tregs and overcome resistance to suppress pancreas cancer
In bioRxiv on 4 March 2025 by Mahadevan, K. K., Maldonado, A. S., et al.
- In vivo experiments,
- Mus musculus (Mouse),
- Immunology and Microbiology
Molecular control of PDPNhi macrophage subset induction by ADAP as a host defense in sepsis.
In JCI Insight on 4 February 2025 by Zhang, P., Wang, X., et al.
PubMed
Induction of podoplanin (PDPN) expression is a critical response of macrophages to LPS stimulation or bacterial infection in sepsis, but how this key process of TLR4-stimulated PDPN upregulation is regulated and the effect of PDPN expression on macrophage function remain elusive. Here, we determined how this process is regulated in vitro and in vivo. PDPN failed to be upregulated in TLR4-stimulated macrophages deficient in adhesion and degranulation-promoting adapter protein (ADAP), which could be rescued by the reconstitution of ADAP. A distinct PDPNhi peritoneal macrophage (PM) subset, which exhibited an M2-like phenotype and enhanced phagocytic activity, was generated in WT but not in ADAP-deficient septic mice. The blockade of PDPNhi PMs mimicked the effect of ADAP deficiency, which exacerbated sepsis. Mechanistically, Bruton's tyrosine kinase-mediated (BTK-mediated) tyrosine phosphorylation of ADAP at Y571 worked together with mTOR to converge on STAT3 activation for the transactivation of the PDPN promoter. Moreover, agonist activation of STAT3 profoundly potentiated the PDPNhi PM subset generation and alleviated sepsis severity in mice. Together, our findings reveal a mechanism whereby ADAP resets macrophage function by controlling the TLR4-induced upregulation of PDPN as a host innate immune defense during sepsis.
- Cancer Research
CDK8 remodels the tumor microenvironment to resist the therapeutic efficacy of targeted KRASG12Dinhibition in pancreatic ductal adenocarcinoma
In bioRxiv on 2 February 2025 by McAndrews, K. M., Mahadevan, K. K., et al.
- Cancer Research,
- Immunology and Microbiology
Development of Syngeneic Murine Glioma Models with Somatic Mismatch Repair Deficiency to Study Therapeutic Responses to Alkylating Agents and Immunotherapy.
In Curr Protoc on 1 February 2025 by Bhatt, D., Sundaram, R. K., et al.
PubMed
Glioblastoma (GBM) carries a dismal prognosis, with a median survival of less than 15 months. Temozolomide (TMZ), the standard frontline chemotherapeutic for GBM, is an alkylating agent that generates DNA O6-methylguanine (O6MeG) lesions. Without O6MeG-methyltransferase (MGMT), this lesion triggers the mismatch repair (MMR) pathway and leads to cytotoxicity via futile cycling. TMZ resistance frequently arises via the somatic acquisition of MMR deficiency (MMRd). Moreover, DNA-damaging agents have been shown capable of increasing tumor immunogenicity and improving response to immune checkpoint blockade (ICB), which has had limited success in glioma. The study of how alkylating chemotherapy such as TMZ impacts antitumor immunity in glioma has been hindered by a lack of immunocompetent models that incorporate relevant DNA repair genotypes. Here, we used CRISPR/Cas9 to generate models isogenic for knockout (KO) of Mlh1 in the syngeneic SB28 murine glioma cell line. MMR KO models readily formed intracranial tumors and exhibited in vitro and in vivo resistance to TMZ. In contrast, MMR KO cells maintained sensitivity to KL-50, a newly developed alkylating compound that exerts MGMT-dependent, MMR-independent cytotoxicity. Lastly, MMR KO tumors remained resistant to ICB, mirroring the lack of response seen in patients with somatic MMRd GBM. The development of syngeneic, immunologically cold glioma models with somatic loss of MMR will facilitate future studies on the immunomodulatory effects of alkylating agents in relevant DNA repair contexts, which will be vital for optimizing combinations with ICB. Ā© 2025 Wiley Periodicals LLC. Basic Protocol 1: Validation of mismatch repair knockouts and in vitro sensitivity to alkylating agents Basic Protocol 2: Stereotaxic injection of isogenic SB28 cells in female C57BL/6J mice and in vivo treatment.
- Mus musculus (Mouse),
- Immunology and Microbiology
Targeting the NLRP3 inflammasome abrogates cardiotoxicity of immune checkpoint blockers.
In J Immunother Cancer on 7 January 2025 by Lu, Y., Gao, J., et al.
PubMed
Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of many malignant tumors. However, ICI-induced hyper-immune activation causes cardiotoxicity. Traditional treatments such as glucocorticoids and immunosuppressants have limited effectiveness and may even accelerate tumor growth. This study aimed to identify approaches that effectively reduce cardiotoxicity and simultaneously preserve or enhance the antitumor immunity of ICI therapy.
CTLA4 blockade abrogates KEAP1/STK11-related resistance to PD-(L)1 inhibitors.
In Nature on 1 November 2024 by Skoulidis, F., AraĆŗjo, H. A., et al.
PubMed
For patients with advanced non-small-cell lung cancer (NSCLC), dual immune checkpoint blockade (ICB) with CTLA4 inhibitors and PD-1 or PD-L1 inhibitors (hereafter, PD-(L)1 inhibitors) is associated with higher rates of anti-tumour activity and immune-related toxicities, when compared with treatment with PD-(L)1 inhibitors alone. However, there are currently no validated biomarkers to identify which patients willĀ benefit from dual ICB1,2. Here we show that patients with NSCLC who have mutations in the STK11 and/or KEAP1 tumour suppressor genes derived clinical benefit from dual ICB with the PD-L1 inhibitor durvalumab and the CTLA4 inhibitor tremelimumab, but not from durvalumab alone, when added to chemotherapy in the randomized phase III POSEIDON trial3. Unbiased genetic screens identified loss of both of these tumour suppressor genes as independent drivers of resistance to PD-(L)1 inhibition, and showed that loss of Keap1 was the strongest genomic predictor of dual ICB efficacy-a finding that was confirmed in several mouse models of Kras-driven NSCLC. In both mouse models and patients, KEAP1 and STK11 alterations were associated with an adverse tumour microenvironment, which was characterized by a preponderance of suppressive myeloid cells and the depletion of CD8+ cytotoxic T cells, but relative sparing of CD4+ effector subsets. Dual ICB potently engaged CD4+ effector cells and reprogrammed the tumour myeloid cell compartment towards inducible nitric oxide synthase (iNOS)-expressing tumoricidal phenotypes that-together with CD4+ and CD8+ T cells-contributed to anti-tumour efficacy. These data support the use of chemo-immunotherapy with dual ICB to mitigate resistance to PD-(L)1 inhibition in patients with NSCLC who have STK11 and/or KEAP1 alterations.
- Biochemistry and Molecular biology,
- Cancer Research
CDK12 loss drives prostate cancer progression, transcription-replication conflicts, and synthetic lethality with paralog CDK13.
In Cell Rep Med on 15 October 2024 by Tien, J. C., Luo, J., et al.
PubMed
Biallelic loss of cyclin-dependent kinase 12 (CDK12) defines a metastatic castration-resistant prostate cancer (mCRPC) subtype. It remains unclear, however, whether CDK12 loss drives prostate cancer (PCa) development or uncovers pharmacologic vulnerabilities. Here, we show Cdk12 ablation in murine prostate epithelium is sufficient to induce preneoplastic lesions with lymphocytic infiltration. In allograft-based CRISPR screening, Cdk12 loss associates positively with Trp53 inactivation but negatively with Pten inactivation. Moreover, concurrent Cdk12/Trp53 ablation promotes proliferation of prostate-derived organoids, while Cdk12 knockout in Pten-null mice abrogates prostate tumor growth. In syngeneic systems, Cdk12/Trp53-null allografts exhibit luminal morphology and immune checkpoint blockade sensitivity. Mechanistically, Cdk12 inactivation mediates genomic instability by inducing transcription-replication conflicts. Strikingly, CDK12-mutant organoids and patient-derived xenografts are sensitive to inhibition or degradation of the paralog kinase, CDK13. We therein establish CDK12 as a bona fide tumor suppressor, mechanistically define how CDK12 inactivation causes genomic instability, and advance a therapeutic strategy for CDK12-mutant mCRPC.
TCF-1 and TOX regulate the memory formation of intestinal group 2 innate lymphoid cells in asthma.
In Nat Commun on 8 September 2024 by Bao, K., Gu, X., et al.
PubMed
Immune memory has been expanded to group 2 innate lymphoid cells (ILC2s), but the cellular and molecular bases remain incompletely understood. Based on house dust mite (HDM)-induced mice asthma models and human samples, we applied flow cytometry, parabiosis, in vivo imaging and adoptive transplantation to confirm the persistence, migration and function of CD45+lineage-CD90.2+NK1.1-NKp46-ST2-KLRG1+IL-17RB+ memory-like ILC2s (ml-ILC2s). Regulated by CCR9/CCL25 and S1P signaling, ml-ILC2s reside in the lamina propria of small intestines (siLP) in asthma remission, and subsequently move to airway upon re-encountering antigens or alarmins. Furthermore, ml-ILC2s possess properties of longevity, potential of rapid proliferation and producing IL-13, and display transcriptional characteristics with up-regulation of Tox and Tcf-7. ml-ILC2s transplantation restore the asthmatic changes abrogated by Tox and Tcf7 knockdown. Our data identify siLP ml-ILC2s as a memory-like subset, which promotes asthma relapse. Targeting TCF-1 and TOX might be promising for preventing asthma recurrence.
- Immunology and Microbiology
Transcriptomic, clonal, and functional analyses reveal Liver tissue-imprinted immuno-profile of circulating autoreactive CD4 T cells in autoimmune liver diseases
In bioRxiv on 29 March 2024 by Cardon, A., GuinebretiĆØre, T., et al.
- Cancer Research
CDK12Loss Promotes Prostate Cancer Development While Exposing Vulnerabilities to Paralog-Based Synthetic Lethality
In bioRxiv on 21 March 2024 by Tien, J. C., Chang, Y., et al.
- Cancer Research,
- Immunology and Microbiology
Antitumor Effect by Either FLASH or Conventional Dose Rate Irradiation Involves Equivalent Immune Responses.
In Int J Radiat Oncol Biol Phys on 15 March 2024 by Almeida, A., Godfroid, C., et al.
PubMed
The capability of ultrahigh dose rate FLASH radiation therapy to generate the FLASH effect has opened the possibility to enhance the therapeutic index of radiation therapy. The contribution of the immune response has frequently been hypothesized to account for a certain fraction of the antitumor efficacy and tumor kill of FLASH but has yet to be rigorously evaluated.
- Cancer Research
Somatic mouse models of gastric cancer reveal genotype-specific features of metastatic disease.
In Nat Cancer on 1 February 2024 by Leibold, J., Tsanov, K. M., et al.
PubMed
Metastatic gastric carcinoma is a highly lethal cancer that responds poorly to conventional and molecularly targeted therapies. Despite its clinical relevance, the mechanisms underlying the behavior and therapeutic response of this disease are poorly understood owing, in part, to a paucity of tractable models. Here we developed methods to somatically introduce different oncogenic lesions directly into the murine gastric epithelium. Genotypic configurations observed in patients produced metastatic gastric cancers that recapitulated the histological, molecular and clinical features of all nonviral molecular subtypes of the human disease. Applying this platform to both wild-type and immunodeficient mice revealed previously unappreciated links between the genotype, organotropism and immune surveillance of metastatic cells, which produced distinct patterns of metastasis that were mirrored in patients. Our results establish a highly portable platform for generating autochthonous cancer models with flexible genotypes and host backgrounds, which can unravel mechanisms of gastric tumorigenesis or test new therapeutic concepts.
- Mus musculus (Mouse),
- Cancer Research,
- Immunology and Microbiology
CD4 T cell-activating neoantigens enhance personalized cancer vaccine efficacy.
In JCI Insight on 8 December 2023 by Huff, A. L., Longway, G., et al.
PubMed
Personalized cancer vaccines aim to activate and expand cytotoxic antitumor CD8+ T cells to recognize and kill tumor cells. However, the role of CD4+ T cell activation in the clinical benefit of these vaccines is not well defined. We previously established a personalized neoantigen vaccine (PancVAX) for the pancreatic cancer cell line Panc02, which activates tumor-specific CD8+ T cells but required combinatorial checkpoint modulators to achieve therapeutic efficacy. To determine the effects of neoantigen-specific CD4+ T cell activation, we generated a vaccine (PancVAX2) targeting both major histocompatibility complex class I- (MHCI-) and MHCII-specific neoantigens. Tumor-bearing mice vaccinated with PancVAX2 had significantly improved control of tumor growth and long-term survival benefit without concurrent administration of checkpoint inhibitors. PancVAX2 significantly enhanced priming and recruitment of neoantigen-specific CD8+ T cells into the tumor with lower PD-1 expression after reactivation compared with the CD8+ vaccine alone. Vaccine-induced neoantigen-specific Th1 CD4+ T cells in the tumor were associated with decreased Tregs. Consistent with this, PancVAX2 was associated with more proimmune myeloid-derived suppressor cells and M1-like macrophages in the tumor, demonstrating a less immunosuppressive tumor microenvironment. This study demonstrates the biological importance of prioritizing and including CD4+ T cell-specific neoantigens for personalized cancer vaccine modalities.
- Cancer Research,
- Immunology and Microbiology
Differential requirements for CD4+ T cells in the efficacy of the anti-PD-1+LAG-3 and anti-PD-1+CTLA-4 combinations in melanoma flank and brain metastasis models.
In J Immunother Cancer on 6 December 2023 by Phadke, M. S., Li, J., et al.
PubMed
Although the anti-PD-1+LAG-3 and the anti-PD-1+CTLA-4 combinations are effective in advanced melanoma, it remains unclear whether their mechanisms of action overlap.
- Mus musculus (Mouse),
- Immunology and Microbiology
Local and distant response to intratumoral immunotherapy assessed by immunoPET in mice.
In J Immunother Cancer on 1 November 2023 by Meyblum, L., Chevaleyre, C., et al.
PubMed
Despite the promising efficacy of immune checkpoint blockers (ICB), tumor resistance and immune-related adverse events hinder their success in cancer treatment. To address these challenges, intratumoral delivery of immunotherapies has emerged as a potential solution, aiming to mitigate side effects through reduced systemic exposure while increasing effectiveness by enhancing local bioavailability. However, a comprehensive understanding of the local and systemic distribution of ICBs following intratumoral administration, as well as their impact on distant tumors, remains crucial for optimizing their therapeutic potential.To comprehensively investigate the distribution patterns following the intratumoral and intravenous administration of radiolabeled anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and to assess its corresponding efficacy in both injected and non-injected tumors, we conducted an immunoPET imaging study.
- Cancer Research,
- Immunology and Microbiology
KRASG12D inhibition reprograms the microenvironment of early and advanced pancreatic cancer to promote FAS-mediated killing by CD8+ T cells.
In Cancer Cell on 11 September 2023 by Mahadevan, K. K., McAndrews, K. M., et al.
PubMed
The KRASG12D mutation is present in nearly half of pancreatic adenocarcinomas (PDAC). We investigated the effects of inhibiting the KRASG12D mutant protein with MRTX1133, a non-covalent small molecule inhibitor of KRASG12D, on early and advanced PDAC and its influence on the tumor microenvironment. Employing 16 different models of KRASG12D-driven PDAC, we demonstrate that MRTX1133 reverses early PDAC growth, increases intratumoral CD8+ effector TĀ cells, decreases myeloid infiltration, and reprograms cancer-associated fibroblasts. MRTX1133 leads to regression of both established PanINs and advanced PDAC. Regression of advanced PDAC requires CD8+ TĀ cells and immune checkpoint blockade (ICB) synergizes with MRTX1133 to eradicate PDAC and prolong overall survival. Mechanistically, inhibition of KRASG12D in advanced PDAC and human patient derived organoids induces FAS expression in cancer cells and facilitates CD8+ TĀ cell-mediated death. Collectively, this study provides a rationale for a synergistic combination of MRTX1133 with ICB in clinical trials.
- Cancer Research,
- Immunology and Microbiology
The GPCR-GĪ±s-PKA signaling axis promotes T cell dysfunction and cancer immunotherapy failure.
In Nat Immunol on 1 August 2023 by Wu, V. H., Yung, B. S., et al.
PubMed
Immune checkpoint blockade (ICB) targeting PD-1 and CTLA-4 has revolutionized cancer treatment. However, many cancers do not respond to ICB, prompting the search for additional strategies to achieve durable responses. G-protein-coupled receptors (GPCRs) are the most intensively studied drug targets but are underexplored in immuno-oncology. Here, we cross-integrated large singe-cell RNA-sequencing datasets from CD8+ T cells covering 19 distinct cancer types and identified an enrichment of GĪ±s-coupled GPCRs on exhausted CD8+ T cells. These include EP2, EP4, A2AR, Ī²1AR and Ī²2AR, all of which promote T cell dysfunction. We also developed transgenic mice expressing a chemogenetic CD8-restricted GĪ±s-DREADD to activate CD8-restricted GĪ±s signaling and show that a GĪ±s-PKA signaling axis promotes CD8+ T cell dysfunction and immunotherapy failure. These data indicate that GĪ±s-GPCRs are druggable immune checkpoints that might be targeted to enhance the response to ICB immunotherapies.
